Polynitro alcohols and their method of preparation



United States Patent 3,020,318 POLYNITRO ALCOHOLS AND THEIR METHOD 0F PREPARATION Marvin H. Gold and Gustave B. Linden, Pasadena, Calif., assignors to Aerojet-General Corporation, Azusa, Califi, a corporation of Ohio No Drawing. Filed July 25, 1957, Ser. No. 675,799

14 Claims. ((11. 260-632) This invention relates to new and useful polynitro alcohols and to a method for their preparation. In particular, this invention is directed to polynitro alcohols having the general formula:

wherein A is either an alkylene or nitroalkylene radical.

The polynitro alcohols of our invention find valuable use as intermediates in the preparation of high explosive compounds. For example, 4,4,4-trinitrobutanol can be condensed with methyl isocyanate according to the method disclosed in assignees copending United States patent application Serial No. 482,410, filed January 17, 1955, now U.S..Patent No. 2,978,492, to yield N methyl 4,4,4-trino-- trobutyl carbar'nate. The compounds thus prepared are useful as high explosives and can be used in any conventional explosive missile, projectile, rocket, or the like, as the main explosive charge. An example of such a missile is disclosed in United States Patent Number 2,470,162, issued May 17, 1949. One way of using the high exploives in a device such as that disclosed in United States Patent No. 2,470,162 is to pack the crystalline explosive in powder form into the warhead of the missile. Alternatively, the crystals can be first pelletized and then; packed. A charge thus prepared is sufficiently insensitive to withstand the shock entailed in the ejection of a shell from a gun barrel or from'a rocket launching tube under the pressure developed from ignition of a propellant charge, and can be caused to explode on operation of an impactor time-fuse mechanism firing a detonating explosive such as lead azide or mercury fulminate.

1 It is well known that acyl halides may be reduced to their corresponding alcohols with reducing agents such as lithium aluminum hydride, and hydrogen in the presence of a catalyst. However, these conventional reducing agents all possess such strong reducing properties that the destruction of functional groups, such as aliphatic nitro groups, usually accompanies the reduction of the carbonyl group. This method of further complicated by the sensitivity of nitro groups to basic media, hence these reducing agents, although capable of effecting the reduction, nevertheless have many undesirable features making it advantageous to find some more convenient method.

We have now found that polynitro alcohols can be prepared from their corresponding acyl halides by reduction with sodium borohydride in accordance with the general reaction scheme set forth below:

wherein A is an alkylene or nitroalkylene radical, and X is a halogen radical.

The reduction is effected by adding a solution of a nitrocontaining acyl halide to a suspension of sodium borohydride.

Optimum results are obtained using a suspension of powdered sodium borohydride, about 200% excess, in an inert solvent such as dioxane.

1,4-dioxane is the preferred solvent due to its inert A behavior and volatility. be used such as 2,4-dimethylsulfolane; however, dioxane Any inert organic solvent can is preferred since it can "be separated from the product with greater ease.

The compounds thus produced are obtained in a relatively pure form from the reaction mixture by hydrolyzing the sodium borohydride and its oxidation products in the aqueous phase, with a mineral acid, and recovering the product by crystallization,extraction or distillation from the non' aqueous phase.

The following example is presented to more clearly illustrate our invention. This example is presented purely as a means of illustration and does not in any way define either the limits or the scope of our invention.

dioxane and 3.2 gm. (0.07 mole). sodium borohydride, which had been well ground in a ball mill. The mixture was distilled and additional dioxane was periodically.

added until the distillate was no longer basic.

Heating ofthe mixture was then. discontinued and a solution of 0.6 ml. (0.01 mole) acetic acid in 10 dioxane was added dropwise to the sodium borohydride suspension. The distillation apparatus was removed and utes during which time the temperature of the reaction replaced with an internalthermometer. A solution of 4.8 gm. (0.02 mole) 4,4,4-trinitrobutyryl chloride in20 ml. dioxane was added dropwise over aperiod of minmixture was maintained between 15 C. and 20 C. The reaction was mildly exothermic during the first hour and the mixture had a very pale yellow color. The reaction mixture was hydrolyzed with 20 ml. 50:50 water-acetic acid and 20 ml. 2 N hydrochloric acid and the resulting clear solution was evaporated almost to dryness under vacuum. Water was added and the product was extracted with'ether. The ethersolution was washed with saturated sodium chloride and diluted with benzene. The solution was dried 2 hours over anhydrous sodium sulfate, then i filtered and evaporated to dryness at room temperature under vacuum to yield 3.0 gm. of yellow oil, n =1.47l6, B.P. ll0 C./0.5 mm.

The'product, an oil, was fractionally distilled at reduced pressure at a temperature of about 80 to C. to yield a colorless mobile fluid, n =l.4720, B.P. 80-l10 C./ 0.5 mm. The elemental analysis of the product is as follows:

Calculated: percent C, 22.97; percentH, 3.37; percent N,

Found: percent C, 23.48; percent H, 3.50; percent N,

The 4,4,4-trinitrobutyl-p-nitrobenzoate' derivative was prepared by treating the product with nitrobenzoyl chloride in the conventional manner. The derivative had a melting point of 1131 14 C. and the following analysis:

Calculated: percent C, 36.88; percent H, 2.81; percent N,

Found: percent C, 37.21; percent H, 2.93; percent N,

containing aldehyde followed by oxidation to the desired acid.

Other members of the class of compounds of our invention are prepared in the manner described above; for example, 3,3,3-trinitropropanol; 4,4,6,6,6-pentanitro-1- hexanol; 4,4,6,6,8,8,S-heptanitro-l-octanol; and 4,4,6,8,8, 8-hexanitro-1-octanol are prepared by reducing 3,3,3-t-rinitropropanoyl chloride; 4,4,6,6,G-pentanitro-hexanoyl chloride; 4,4,6,6,8,8,8-heptanitro-octanoyl chloride and 4,4,6,8,8,8-heXanitro-octanoyl chloride respectively with sodium borohydride in accordance with the teachings of this invention. It will be appreciated by those skilled in the art that other members of this new class of compounds can be prepared in the same manner simply by reacting appropriate starting materials. It is preferred in the practice of our invention to utilize polynitro acid chlorides as starting materials for reasons of cost and convenience, however it should be understood that any of the acid halides can be used. It will also be appreciated that reaction temperatures are not critical in the practice of our invention, and that both higher and lower temperatures and conditions can be used if desired without affecting the course of the reaction.

This application is a continuation in part of our copending U.S. patent application Serial No. 392,471, filed November 16, 1953, now abandoned.

We claim:

1. As compositions of matter the polynitro alcohols having the general formula:

wherein A is a radical selected from the group consisting of lower alkylene and lower nitroalkylene radicals. 7

'2. As a composition of matter, 4,4,4-trinitro-l-butanol having the structural formula 3. As a composition of matter 3,3,3-trinitro1-propanol having the structural formula 4. As a composition of matter 4,4,6,6,6-pehtanitro-1- hexanol having the structural formula:

5. As a composition of matter 4,4,6,6,8,8,8-heptanitrol-octanol having the structural formula:

IIIO: T N02 NOr-C-CHz-C-CH3-CGHzCHaCHgOH NO: NO: NO:

6. As a composition of matter 4,4,6,8,8,8-hexanitro-loctanol having the structural formula:

1 0. No, not Nor-o-onr-on-om-o-wmomomon 7. A method of preparing polynitro alcohols having the general formula:

which comprises reducing a polynitro acid halide having the general formula:

with sodium borohydride wherein A is a radical selected from the group consisting of lower alkylene and lower nitroalkylene radicals and X is a halogen radical.

8. The method of claim 7 wherein the reaction is con- I ducted in the presence of an inert organic solvent.

9. The method of claim 7 wherein the reaction is conducted inthe presence of 1,4-dioxane.

' 10. The method of preparing 4,4,4-trinitro-1-butanol which comprises reducing 4,4,4-trinitrobutyryl chloride with sodium borohydride.

11. The method of preparing 3,3,3-trinitro-l-propanol which comprises reducing 3,3,3trinitro-propanoyl chloride with sodium borohydride.

12. The method of preparing 4,4,6,6,6-pentanitro-1- hexanol which comprises reducing 4,4,6,6,6-pentanitrohexanoyl chloride with sodium borohydride.

13. The method of preparing 4,4,6,6,8,8,8-heptanitr l-octanol which comprises reducing 4,4,6,6,8,8,8-heptanitro-octanoyl-chloride with sodium borohydride.

14. The method of preparing 4,4,6,8,8,8-hexanitro-loctanol which comprises reducing 4,4,6,8,8,8-hexanitrooct'anoyl chloride with sodium borohydride.

References Cited in the file of this patent FOREIGN PATENTS 698,138 Great Britain Oct. 7, 1953 OTHER REFERENCES Hurd: Chemistry of the Hydrides, New York, John Wiley & Sons, Inc. (1952), p. 162.

Schechter et al.: J.A.C.S., vol. 74 (1952), pp. 3664-8. 

1. AS COMPOSITION OF MATTER THE POLYNITRO ALCOHOLS HAVING THE GENERAL FORMULA: 